Pretty Poisons
The Amazon’s most colorful and toxic frogs are also its most physically fit. Biologists subjected individuals from more than 50 frog species to fitness tests, measuring oxygen uptake as the amphibians walked in a rotating plastic tube. When it came to overall aerobic capacity, brightly hued poison frogs topped their dreary-colored relatives. The deadly beauties’ lifestyle forces them to stay in top form. They’re constantly searching for their food and poison source: ants and mites with toxic alkaloids that the amphibians transport into their skin. “They have to shop to keep the toxicity all the time,” says lead author Juan Santos, of the National Evolutionary Synthesis Center in North Carolina. Talk about a killer workout.—Susan CosierBack to Top

Killer Colors
Wind turbines twirl against the sky in unobtrusive shades of white and gray. But even modest hues may lure bugs—and, in turn, pose a potentially fatal attraction for hungry birds and bats. To find out which colors are most alluring to insects, British researchers randomly placed cards of each of 11 different colors—ranging from bright white to sky blue to red—near the base of a wind tower at midday and after dusk for 10 minutes. Yellow, universal for pollen, was most irresistible. Next were white and light gray, which a fly or moth might take for foliage, since leaves reflect the white end of the light spectrum. Surprisingly, black also proved attractive, perhaps because it absorbs heat. Purple was least appealing—but that doesn’t mean all windmills need go grape. “The fact that one color was significantly less attractive indicates there are others,” says Chloe Long, who notes the ultraviolet and infrared qualities of paint are important factors, too. Though preliminary, the findings indicate that plans for wildlife-friendly wind power shouldn’t be color-blind.—Nick NeelyBack to Top

Lickety-Split
For nearly two centuries ornithologists have thought that hummingbirds drink by capillary action—using their forked tongues like tiny straws to draw liquid up by surface tension. In fact, the tongue acts more like a trap than a tube, say findings published in the Proceedings of the National Academy of Sciences. Using high-speed camera shots of 10 species and microscopic postmortem examinations of four, including the ruby-throated hummingbird and the buff-tailed coronet, University of Connecticut researchers found that the fleet fliers use tiny hairlike structures called lamellae to trap nectar. They splay their millimeter-thick tongue as it hits the liquid, and the lamellae lining either side extend—much like unzipping a zipper. When the tongue retracts, the hairs roll inward and trap the nectar as the two sides zip closed, drawing in the liquid. The entire motion takes as little as 1/20th of a second. The next question: How do hummingbirds swallow? The authors write, “The mechanics of this crucial last step of nectar feeding is completely unknown.”—Alisa Opar Back to Top

Survivor
“It’s kind of a bright spot in this whole tsunami saga,” says John Klavitter, Midway Atoll National Wildlife Refuge deputy manager, of Wisdom, the world’s most famous albatross. The bird, a 60-year-old Laysan banded in 1956, and her latest chick—something like her 35th—survived the mid-March waves that crashed over the refuge’s islands and, coupled with two earlier storms, killed 110,000 Laysan and black-footed albatross chicks, 2,000 adult birds, and thousands of Bonin petrels. For two weeks post-tsunami, Wisdom disappeared (she was likely at sea seeking food for her baby), but she finally returned to her nest on unharmed Sand Island. “There are a lot of sad stories in conservation,” Klavitter adds. “Here’s a story that gives us hope.”—Michele WilsonBack to Top

Plant Smarts
The Venus flytrap has long been known to catch its dinner, snapping shut when an insect touches the tiny hairs on its leaves. Now scientists are realizing that a wide variety of plants exhibit behaviors. “I was raised to believe that plants are plants: You eat them, you grow them, and they look pretty,” says University of Alberta ecologist J.C. Cahill. He’s among those starting to change that viewpoint.

Scientists have discovered, for instance, that some plants distinguish predator insects from pollinators, or strengthen and elongate their roots through dry soil. Plants also give off electrical impulses in response to threats. Polygraph expert and former CIA interrogation specialist Cleve Backster confirmed this when, on an impulse, he hooked up a tropical dracaena to a polygraph and threatened the plant with a flame. The dracaena displayed the same electrical signals that people do when they lie. From lettuce to bananas, the results were similar.

Biologists Ian Baldwin and Jack Schultz have published work suggesting that some plants can communicate through the air. When the researchers threatened poplars and maples they found that nearby trees with no physical contact released defensive chemicals that inhibit digestion, thus hindering predators’ ability to consume the trees’ leaves or bark.

Cahill’s research reveals that some plants grow their roots based on location, resources, and neighbors. His conclusion: “I think we’re at the cusp of a real paradigm shift and that people are going to be viewing plants very differently in the next 10 years, with a much more holistic view of what plants actually are.”—Nathan EhrlichBack to Top